1. Field of the Invention
The present invention relates in general to graphics processing systems and, more particularly, to graphics systems consisting of rasterization hardware used to produce three-dimensional graphical representations of data. Still more particularly the present invention relates to a system in which transparent materials are supported and rendered and, even more particularly, where polarization states are accounted for when producing the graphical representations of transparent objects.
2. Background and Related Art
Computer graphics systems are widely used in a variety of applications in which there is a need to visualize non-opaque media. For example, when designing a car it is advantageous to be able to include the geometric description of the windshield in the model without the windshield obscuring the view of the car's cabin. In a graphics system a partially transparent object is used to represent the window. In general the light transmitted through a transparent object is a function of the coherency state of the incident light.
The light associated with specular reflections has a high degree of polarization. In current computer graphics systems, no account is taken of the polarization state that exists in either the light incident on a surface or the polarization state of the light that ultimately reaches the viewer. For example, in a physically realistic model, if a specular reflection is seen through a non-opaque object of some sort (possibly a filter) the intensity of the specular highlight relates strongly to the polarizing properties of the intervening medium, and the relative orientations of the surface and intervening medium.
The current invention is directed towards providing a means by which the intensity of a specular reflection can be more accurately tempered to better represent the effects of polarization on the specularly reflected light.
It will be understood that within the context of this application the terms non-opaque and transparent are used interchangeably.